<html xmlns="http://www.w3.org/1999/xhtml">
<head>
  <bindings xmlns="http://www.mozilla.org/xbl">
    <binding id="foo">
      <content>
        <iframe xmlns="http://www.w3.org/1999/xhtml" src="javascript:void 0"><children xmlns="http://www.mozilla.org/xbl"/></iframe>
      </content>
    </binding>
  </bindings>
</head>
<body>
  <span style="-moz-binding: url(#foo)"></span>
</body>
</html>
